/*
Date:20210423 7:48am
key:常规题
 */
class Solution {
public:
void F(vector<int>&v,TreeNode*root)
{
    if(root!=nullptr)
    {
        F(v,root->left);
        v.push_back(root->val);
        F(v,root->right);
    }
}
    vector<int> inorderTraversal(TreeNode* root) 
    {
        vector<int>v;
        F(v,root);
        return v;
    }
};